


The Square Root of Pi

by Topaz_Eyes



Category: Doctor Who, Doctor Who (2005)
Genre: Angst, Episode Related, Episode Tag, F/M, Hurt/Comfort
Language: English
Status: Completed
Published: 2010-12-22
Updated: 2010-12-22
Packaged: 2017-10-14 00:22:17
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,499
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/143278
Author URL: https://archiveofourown.org/users/Topaz_Eyes/pseuds/Topaz_Eyes
Summary: <blockquote class="userstuff">
              <p>The nightmare did not end when they closed the door on Midnight.</p>
            </blockquote>





	The Square Root of Pi

**Author's Note:**

> I guess this is my obligatory post-"Midnight" fic? So obviously there are spoilers for that episode.
> 
> Also, please see these wonderful vids by [](http://sunnsea.livejournal.com/profile)[**sunnsea**](http://sunnsea.livejournal.com/), made to go with! [We Must Not Look At Goblin Men](http://sunnsea.livejournal.com/6049.html) and [Fanfic Promo](http://sunnsea.livejournal.com/25493.html).

The nightmare did not end when they closed the door on Midnight.

At first, it looked like it might. After their conversation at the poolside table, the Doctor had perked up, and strode with purpose through the corridors of the Pleasure Palace, straight towards the owner-manager's office. There, he spent a good fifteen minutes shouting to ensure the resort would be shut down yesterday. Donna had shouted some herself. Watching the beetle-sized man cower under their combined onslaught was well worth it.

They headed back to the TARDIS right after. But as soon as the TARDIS door closed, the Doctor visibly sagged, and Donna realized the nightmare was far from over.

He leaned against the wood for a long minute, his head bowed. Donna approached him but he waved her off; she hovered nearby, instead, ready to help him if he needed. He managed to haul himself up and approached the console. He steered them into the Vortex, twisting dials, flipping levers and smacking with the mallet all in the right order, but there was no heart in it.

"Do you want something to eat?" Donna ventured, after the Doctor set the hand brake. It was a practical question: they never did get to that gravity restaurant. More than that, though, she simply needed to hear his voice. "Soup, or toast, or--?"

"I'm not hungry," the Doctor said.

"Are you sure? It won't take a tick--"

"I'm sure." He waved vaguely in the direction of the console. "I'm gonna--the lockdown stabilizers seem to be drifting a bit, I'd better have a look. Don't want to drift too close to the 1980s again." His brittle grin did not touch his eyes.

Donna had learned enough about piloting the TARDIS to recognize the lie. She opened her mouth to call him on it. "Doctor--" she began. Stop deflecting, stop closing yourself off. She then recalled how he'd looked when he returned from the Crusader, and she held her tongue.

"When--if--you want to talk, you know where to find me," Donna said instead. She squeezed his arm gently and left his side, treading down the ramp to the interior.

At the bottom of the ramp, she snuck a peek backwards. From her vantage point, he stood in profile in the middle of the room, staring down at the hand brake. His hand hovered over it, trembling; then it closed into a white, tight fist.

Dejected, Donna headed to the kitchen. She wasn't hungry either, far from it, but she forced herself to eat two slices of toast. Afterward, she sat at the table, her hands curled around a mug of steaming tea.

"'I'm always all right', my arse," she muttered.

She'd seen him in grief and despair, but this was a different kind of broken. She'd felt it in their hug when he returned from the Crusader 50 shuttle. How he'd clutched her, as if she were his sole lifeline in the universe--

No, it was more than that. The Doctor wasn't just broken. He was _defeated_. And she didn't know how to deal with it.

Donna felt the tension in the ship, too. The TARDIS was at least semi-sentient; she was keenly attuned to the emotions of her occupants, and the TARDIS knew the Doctor better than she did. If only the TARDIS could talk, she thought, let her know what was really going on in her Spaceman's mind.

The ship's tone hit a melancholy key, as if she were at a loss as well. "Then it's much worse than I thought," Donna murmured, "if he won't talk to you either. Oh, Spaceman."

The TARDIS chimed her affirmative.

Mulling it over wasn't going to make it any better though. And it was late, long past time for her to go to bed. She decided to wait and see where things led.

She stopped by the library first to pick out a novel. Something light maybe, Agatha Christie. She selected a slim, dog-eared volume. She then wended back round the corridors to peek into the control room again, but it was empty; the Doctor had disappeared to God knew where. Sighing, she retired to her own room to prepare for bed.

Dressed in her nightshirt, bundled under her duvet, she tried to read but couldn't concentrate. The words rolled all over the page like beads unraveling from a string. After a half-hour of staring at the same ten pages she gave up and turned out the light.

She was still wide awake, lying in the uneasy dark, when the soft knock on her door came about half an hour later.

"Donna? Are you still up?"

She heard an edge of--something in his voice. Desperation, or need. She sat up. "Door's open, Spaceman."

It opened and the Doctor stepped in the threshold. Bathed in the light of the hallway, his features fell in shadow. She sat up and turned on the bedside lamp; peering at him, he had the same lost, haggard look he'd had on Midnight just after he'd returned from the shuttle. He ran a nervous hand through his hair, but otherwise he didn't reply; he hovered at the doorway, as if he couldn't decide between bolting from the room or joining her.

"Come here," Donna beckoned. She budged over to give him room.

He shuffled across the floor and perched on the edge of her bed. For a minute he sat, eerily stiff. It wasn't until she shifted to touch his shoulder that he turned to face her. Donna could feel the subtle tremor in his muscles under her palm.

"What do you need?" she asked gently.

This close, his eyes were almost black, pleading and haunted in his too-pale face. "Donna," he rasped, "I'm sorry. I'm so sorry." He broke off and stared at her for a long moment, his eyes flickering down to her lips and back up, over and over.

"What do you need, Doctor?" she repeated, though she'd already gleaned the answer. It didn't bother her as much as she thought it would.

He cupped her face in his shaking fingers, swallowing hard. "I need--I'm sorry," he gritted. "I can't. I shouldn't ask."

"Don't be sorry," Donna murmured, leaning her forehead on his. She rubbed his shoulder. "It's all right."

He didn't seem to have heard. "It's not what you want--"

"It's all right," she reiterated firmly, and pulled him to her.

He kissed her then, hard and desperate, already groping for her breasts through her nightshirt. Finding them, he squeezed none too gently. Donna gasped with shock into his mouth; immediately he plunged his tongue inside, his hands roaming greedily up her arms and down her sides.

After a few minutes of what she could only think of as groping, he stopped to rip off his tie and shrug out of his suit jacket. Donna unbuttoned and pushed the button-down shirt off his shoulders. He stripped off the rest of his clothes and tossed them to the floor. While he undressed, Donna wriggled out of her nightshirt and threw it down with the rest of the clothing. The Doctor kissed her again, not with passion but with urgency as they slid down onto the mattress.

He seemed almost frantic as he moved over her, mapping her contours as if she might slip away on him at any moment and he had to sear her into his memory. His fingers dipped roughly to explore between her legs, then he dragged her knickers off. Donna stroked the Doctor's back and sides to try to soothe him, but he trembled in her arms as his arousal grew.

 _Oh, Spaceman._ Aside from his breath whistling between his teeth, the Doctor was silent, and perhaps that was the hardest for her to bear. Her vision blurring, Donna reached up with both hands to cup his face. He closed his eyes at the touch, as if he couldn't bear to look at her. At that, Donna rolled onto her back, pulling the Doctor with her. She opened herself up, guided him to her entrance, and he pushed into her with a strangled moan.

Though once buried inside her, he stilled, rigidly braced on his elbows. Donna looked up to find his eyes open, but focused on something distant that only he could see. The thought of the Doctor spiraling further away from her chilled her to her core. She had to bring him back. So she wrapped her legs around him, arched her hips and pulled him in as deeply as she could.

This seemed to snap the Doctor out of his trance. He sank into her, buried his face in the side of her neck and began to thrust. Donna matched his rhythm and clutched his shoulders as they rocked together. This wasn't sex, it was fucking, plain and simple. But she'd rather the Doctor reach out to her and seek physical comfort in her body like this, than-- She blinked back tears, unable to finish the thought. Instead she concentrated on tangling her fingers in the hair at the nape of his neck and urging him on, until he stiffened and groaned into her hair with his release.

But at least he wasn't totally selfish about it: as soon as he finished, he slid a hand between them and kept thrusting until her own climax followed moments later. After, Donna held him close, letting his weight rest entirely on her, and pretended not to notice the excessive dampness in the crook of her neck. They could deal with the consequences of this later, she thought. After Messaline, the Library and now Midnight, she didn't know how much more the Doctor could take.

A few minutes later, she couldn't help but grunt under the Doctor's weight. For a stick on legs, he was a lot heavier than he looked.

"Ooof, Spaceman, room to breathe, please."

He raised his head, his eyes bleak. "Right. Sorry. I should get going." Brisk now, he withdrew, rolled off and swung his legs over the edge of the bed, avoiding her gaze all the while. "Thank you, Donna."

"Like hell you're leaving, sunshine." She pulled herself up too, and seized his wrist. "I am not a wham-bam-thank-you-ma'am."

He flinched and yanked his arm from her grasp. "No, you're not. I never meant that. But I've totally bollocksed our friendship now, so it's best that I go." He gathered the pile of clothing on the floor.

"There were two of us involved, if you didn't notice. Are you saying I don't know my own mind?"

He avoided her eyes, his posture still. "Not at all. I'm saying I don't know mine right now."

Perhaps that was the most honest admission the Doctor had ever made. "And that's why you're staying here," she replied, gently but firmly, "until you do."

The Doctor sat, reluctant for a minute, but just when Donna was about to yank him back down, he dropped his clothes back onto the floor and climbed back under the covers. Donna gathered him in again and settled his head on her shoulder. He molded his limbs around her and nestled against her with a heavy sigh. The TARDIS, bless her, dimmed all the lights to a dull glow and hushed to a barely-there hum. The Doctor pressed his cheek against the swell of her breast, the flutter of his eyelashes tickling her skin.

Donna stared at the ceiling. There was so much wrong with this. It was supposed to have been a well-earned holiday for him. Instead, four people had died. Almost five. Worse, not only did the Doctor just barely escape his own murder, but also he'd returned empty, shaken--unsure. The entity had stolen more than his voice.

Her own guilt and frustration--with the situation and with herself, because she couldn't help but feel responsible too--rose, and she wanted to lash out. She tried to bite it back, but some escaped anyway.

"I should've been with you back there. Midnight. On that shuttle."

"Donna, don't--" he warned against her breast.

"It wouldn't have happened."

"You don't know that."

"You don't know either."

"Look, it's over and done now," he said wearily, "so let's not--"

"Let's not what? Go there?" She fought back a threatening quaver in her voice. "We're still there, Doctor. We never left."

He turned his back to her, and her last bit of patience snapped. After traveling this long with him she'd learned how to read between the lines, when to push and when to wait, but she couldn't bear it any longer. "Talk to me," she begged, "please. Say something. Anything."

She felt the tension thrum in his body again. At length he replied softly, so softly it was almost like he was only mouthing the words. "The square root of pi is 1.772453850905516027298167483314."

Donna ached at the bleak undertone, but rejoiced in that he'd at last opened up a crack. The Doctor wouldn't mention this if it hadn't been involved somehow. Now she had something to work with. She just had to make him blather until he divulged the rest.

"Bloody computer, you are," she said, not unfondly. "Far as I'm concerned, the only square root of pie is apple. Or peach, or mince--"

She heard his voice quirk, amused at the pun. "Or banana."

"Or banana. Now you're thinking, Spaceman."

"Quite right, too." He turned over to face her, hoisting himself on his elbow. "But you know, Donna, a pie is a circular shape. Its circumference is pi times the diameter, its area is pi times the radius squared. Of course its volume's a little harder to calculate, because the sides of the pie dish are usually flared and you have to account for the angles and the height and the difference in circumference between the top and bottom of the dish, but--"

She rolled her eyes. "Oh, now you're just being a know-it-all."

"I never knew the Hostess' name." He blinked, and swallowed hard. "I knew everyone else's but hers."

Donna could only nod. Of course. Normally he delighted in learning about everyone he met; except the one time he didn't bother was the one time it counted most. The guilt was killing him. She pulled him in and hugged him tight, her eyes welling up. "I'm sorry."

After a minute, he shifted, and she let go. He stared at a point above her shoulder and drew his mouth in a grim line. "She deserved better than that," he whispered.

"Yes, she did," Donna agreed, because it was true, and what else could she say?

They fell into a silence that grew steadily uncomfortable. It wasn't just his guilt over the Hostess, she realized, there was something else he was holding back, too. "What's so important about the square root of pi?"

The Doctor shifted on the pillow. "Pi is a fundamental constant of the universe," he said. "It has different names on other planets. Kr'tarans call it kr'tut, we---Time Lords--called it the unity factor. But its value is the same everywhere in the universe. Like a base code of intelligent life. It's transcendental."

He drew out the enunciation of the last word, rolling it on his tongue. Donna huffed with amusement. His voice then grew distant. "When I tested Sky--the entity--it didn't seem to know it at first. It just parroted it back. Or so I thought."

"But it--it knew?"

"Maybe. Yeah. I think it did. Or if it didn't, I taught it well. Either way it latched on. The rest, as they say, is history," the Doctor finished bitterly.

"It wasn't your fault."

His eyes were old, so old. "Wasn't it?"

"You didn't know. You couldn't have."

"And the Hostess might still be alive if I'd left well enough alone."

He wrenched free from her and sat up on the edge of the bed. Head bowed, shoulders rounded, despair seemed to seep from every pore of him. Donna climbed on her knees to embrace him from behind. He flinched, but didn't pull away.

"I know," she said, her voice gentle. "But you listen to me, Doctor. The fact is, if she hadn't died, you would have." And I can't bear even the thought of losing you, she added silently. "And that entity--that _thing_ \--would have gone back to the Pleasure Palace and do God knows what."

"That's not a comfort, Donna."

"No," Donna said gently, "it's not. It's not meant to be. But it's the truth. And it's all we've got, so we have to make do with it."

He raised his head. "You said 'we.'"

"Yeah. We're both in this." Donna reached down and squeezed his hand. "You are not alone, Spaceman, no matter what you think otherwise."

He raised her hand and pressed it to his cheek. The light dust of stubble rasped her knuckles. "Thank you," he whispered, and dropped their joined hands back on his lap.

"Did you find out after? Her name?"

"Yeah," he said.

"What was it?"

"Her name was Ayira. Ayira Clark."

They fell silent for a moment. Then Donna said, "We owe her everything."

"I know. But I can't make amends, it's too late now."

"Of course you can, Doctor. It's never too late."

He faced her, miserable. "How do I, Donna? She was literally vaporized by the extonic--"

"God, you are thick."

The Doctor drew back, looking wounded, but she pressed on, "You can't make amends to her, no, but you can to her family. After we leave here, we find them and explain to them what really happened. They deserve to know how Ayira Clark kept your skinny arse alive on that shuttle. And they deserve to hear it properly. From you. 'Cause they'll never get the real story from the company, not in a million years."

"And you're sure that will help."

"Yes, it will. They'll probably hate you for it, but at least they'll have the truth. Counts for something."

He nodded. "Right. We'll go back tomorrow, after you've had a rest."

"You too."

Donna lay back down, pulling him with her. This time the Doctor didn't object. He gathered her close and she felt his body at last begin to relax.

The TARDIS dimmed the lights the rest of the way. Pillowed on his narrow chest, she listened to his hearts beat under her ear. Strange, how she lay curled up with the Doctor like this, skin-to-skin without a stitch of clothing on, and she didn't mind. She liked it, in fact. Maybe she was growing soft on him. God forbid--

His voice sliced through the darkness. "Are we okay, Donna?"

She startled at the question, and looked up. The TARDIS helpfully raised the lights enough so she could see him. He was gazing at her intently, his eyes lined with worry. She rose on one elbow. "Of course we're okay. What kind of question is that?"

He gestured between them. "Well, here we are, completely naked because we just had sex."

"Yeah, and your point is--?"

"I thought you never wanted our relationship to turn sexual."

"It's a bit late for that now, Spaceman."

"And you don't mind?"

"If I did, I wouldn't be here now, would I." And in fact, she felt surprisingly at peace with it. "Neither would you, for that matter."

That seemed to appease him, but only for a moment. "So why did you have sex with me?"

She thought for a bit, weighing her words. "There are lots of reasons why humans have sex," she replied carefully.

"I'm aware of that. It wasn't just out of pity? Out of duty?"

She sighed. "Maybe it was, a bit." The Doctor's face fell. She continued, "But mostly because I care about you, you dumbo. I reckon that's reason enough to do things you'd never expect. The best things. The worst things. The craziest things."

He sounded cheeky enough, but his smirk was fragile. "So, which was it? Crazy? Best? Worst?"

All of the above, Donna thought, a little surprised. Out loud she said, "I'm not answering that one, Spaceman." She did smile fondly however, to temper her comment.

"I didn't think you would."

"But yes, we are okay."

His answering smile, though shaky, was relieved. "Good."

"Are you okay, Doctor?"

His grin faded, and he shook his head; in that moment he looked terribly, terribly old. "No. No, I'm not," he admitted.

"And you don't need to be," Donna said. "Not for me."

The Doctor closed his eyes with a heavy sigh. The ship dimmed the lights; Donna settled back down against him and slung her arm possessively across his chest. The universe could bloody well take care of itself until he pulled himself together, she thought, and if the universe had a problem with that, it would have to deal with her. So Donna lay in the darkness, listening to the Doctor's ragged breathing, and waited until the nightmare finally, finally passed.


End file.
